<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<p>您可以通过 selected 属性预选择某些选项。</p>

<form action="/demo/demo_form.asp">
  <select name="cars">
    <option value="volvo">Volvo</option>
    <option value="saab">Saab</option>
    <option value="fiat" selected>Fiat</option>
    <option value="audi">Audi</option>
  </select>
  <br><br>
  <input type="submit">
</form>

</body>
</html>